package com.changgou.web.gateway.filter;

import com.changgou.web.gateway.service.AuthService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

@Component
public class AuthFilter implements GlobalFilter, Ordered {

    private static final String LOGIN_URL = "http://localhost:8001/api/oauth/toLogin";


    @Autowired
    private AuthService authService;

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();

        // 1. 判断当前请求路径是否为登录请求，如果是，直接放行
        String path = request.getURI().getPath();
        if ("/api/oauth/login".equals(path) || !UrlFilter.hasAuthorize(path)) {
            // 直接放行
            return chain.filter(exchange);
        }

        // 2.不是，从cookie中获取jti的值，如果该值不存在，拒绝本次访问
        String jti = authService.getJtiFromCookie(request);
        if (StringUtils.isEmpty(jti)) {
            // 拒绝访问
            /*// 返回没有权限码
            response.setStatusCode(HttpStatus.UNAUTHORIZED);
            return response.setComplete();*/
            // 跳转到登录页面
            return this.toLoginPage(LOGIN_URL+"?FROM="+request.getURI().getPath(),exchange);
        }

        // 3.cookie中存在jti的值，从redis中获取jwt的值，如果jwt值不存在，拒绝本次访问
        String jwt = authService.getJwtFromRedis(jti);
        if (StringUtils.isEmpty(jwt)) {
            // 可能过期，不存在
            /*// 拒绝访问
            response.setStatusCode(HttpStatus.UNAUTHORIZED);
            return response.setComplete();*/
            return this.toLoginPage(LOGIN_URL+"?FROM="+request.getURI().getPath(),exchange);
        }

        // 4. 对当前的请求对象进行增强，让它携带令牌信息
        request.mutate().header("Authorization", "Bearer " + jwt);

        // 携带http Basic认证信息（包含令牌），放行
        return chain.filter(exchange);
    }

    // 跳转登录页面
    private Mono<Void> toLoginPage(String loginUrl, ServerWebExchange exchange) {
        ServerHttpResponse response = exchange.getResponse();
        response.setStatusCode(HttpStatus.SEE_OTHER);
        response.getHeaders().set("Location",loginUrl);
        return response.setComplete();
    }

    @Override
    public int getOrder() {
        return 0;
    }
}
